[Crash-utility] [PATCH v2] arm64: use the vmcore info to get module/vmalloc/vmemmap ranges

[HAGIO KAZUHITO(萩尾 一仁)]

-----Original Message-----
> The kernel patch has been merged:
>      "arm64: crash_core: Export MODULES, VMALLOC, and VMEMMAP ranges"
>      https://git.kernel.org/arm64/c/2369f171d5c5
> 
> and it will be available in v5.18-rc1.
> 
> So we can get module/vmalloc/vmemmap ranges from the vmcore info
> since the v5.18, and we have no need to calculate them by hand
> any more.
> 
> This patch adds a new hook arm64_get_range_v5_18 which could parse
> out all the module/vmalloc/vmemmap ranges from the vmcore info.
> 
> Signed-off-by: Huang Shijie <shijie at os.amperecomputing.com>
> ---
> v1-->v2:
> 	1.) Change return types to TRUE/FALSE
> 	    for arm64_get_vmcoreinfo_ul().
> 
> 	2.) Change version limit from LINUX(99,0,0) to LINUX(999, 0, 0)
> 	    I guess LINUX(99, 0, 0) can be used for 25 years,
> 	    so I extended to LINUX(999,0,0).

(I think that 9.x is possible and 99.x is unlikely in 25 years.. but ok,
the current versioning scheme might change :)

Acked-by: Kazuhito Hagio <k-hagio-ab at nec.com>

Thank you for the kernel and crash patches to improve!

Kazu

> 
> 	3.) Tested this patch with the live system mode.
> 	    (linux-next kernel + Crash)
> 
> ---
>  arm64.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 47 insertions(+), 2 deletions(-)
> 
> diff --git a/arm64.c b/arm64.c
> index 2dcef46..e3fa316 100644
> --- a/arm64.c
> +++ b/arm64.c
> @@ -560,6 +560,48 @@ static int arm64_get_struct_page_max_shift(struct machine_specific *ms)
>  	return (int)ceil(log2(ms->struct_page_size));
>  }
> 
> +/* Return TRUE if we succeed, return FALSE on failure. */
> +static int arm64_get_vmcoreinfo_ul(unsigned long *vaddr, const char* label)
> +{
> +	char *string = pc->read_vmcoreinfo(label);
> +
> +	if (!string)
> +		return FALSE;
> +
> +	*vaddr  = strtoul(string, NULL, 0);
> +	free(string);
> +	return TRUE;
> +}
> +
> +/*
> + *  The change is caused by the kernel patch since v5.18-rc1:
> + *    "arm64: crash_core: Export MODULES, VMALLOC, and VMEMMAP ranges"
> + */
> +static struct kernel_range *arm64_get_range_v5_18(struct machine_specific *ms)
> +{
> +	struct kernel_range *r = &tmp_range;
> +
> +	/* Get the MODULES_VADDR ~ MODULES_END */
> +	if (!arm64_get_vmcoreinfo_ul(&r->modules_vaddr, "NUMBER(MODULES_VADDR)"))
> +		return NULL;
> +	if (!arm64_get_vmcoreinfo_ul(&r->modules_end, "NUMBER(MODULES_END)"))
> +		return NULL;
> +
> +	/* Get the VMEMMAP_START ~ VMEMMAP_END */
> +	if (!arm64_get_vmcoreinfo_ul(&r->vmemmap_vaddr, "NUMBER(VMEMMAP_START)"))
> +		return NULL;
> +	if (!arm64_get_vmcoreinfo_ul(&r->vmemmap_end, "NUMBER(VMEMMAP_END)"))
> +		return NULL;
> +
> +	/* Get the VMALLOC_START ~ VMALLOC_END */
> +	if (!arm64_get_vmcoreinfo_ul(&r->vmalloc_start_addr, "NUMBER(VMALLOC_START)"))
> +		return NULL;
> +	if (!arm64_get_vmcoreinfo_ul(&r->vmalloc_end, "NUMBER(VMALLOC_END)"))
> +		return NULL;
> +
> +	return r;
> +}
> +
>  /*
>   *  The change is caused by the kernel patch since v5.17-rc1:
>   *    "b89ddf4cca43 arm64/bpf: Remove 128MB limit for BPF JIT programs"
> @@ -765,8 +807,11 @@ static struct kernel_range *arm64_get_range_v5_0(struct machine_specific *ms)
> 
>  static struct kernel_va_range_handler kernel_va_range_handlers[] = {
>  	{
> -		LINUX(5,17,0),
> -		LINUX(99,0,0), /* Just a boundary, Change it later */
> +		LINUX(5,18,0),
> +		LINUX(999,0,0), /* Just a boundary */
> +		get_range: arm64_get_range_v5_18,
> +	}, {
> +		LINUX(5,17,0), LINUX(5,18,0),
>  		get_range: arm64_get_range_v5_17,
>  	}, {
>  		LINUX(5,11,0), LINUX(5,17,0),
> --
> 2.30.2